I am a 1st time BMW owner of a '98 328iC. The car runs well , looks great and has 78000 miles on it. I am looking for advice on upkeep, service, things I'll need to do with the mileage it has. Do I need to only service it at a BMW dealer? Would that include oil changes and such? I'm not mecahnically adept so I owuldn't be doing it my self. I live in the Chicagoland area and plan to garage it until May and not use til then. But if there are servicing issues that I need to be aware of(new brakes etc) I'd like to try to do during this down time. Any advice would be welcome. Thsi is my first time owning a high end car.

Rule #1: If you have the money....and chances are you do if you can by a 98 e36...by all means GO to the dealership and have them run a diagnostic and if there is anything to repair or replace then go elsewhere if you must....but be wary of the popular term "local mechanic". One thing I realized is that "local mechanics" 90% of the time don't work much with foreign cars to be experts on them and they tend to open up their cash registers when they see your BMW drive up and love to overcharge you for basic stuff. MOST OF THE TIME if they are honest they may order parts you need from the very BMW dealership you avoided and charge you extra for shipping and handling fees. If they are not honest then they'll give you shitty non-OEM parts and charge you as if they ordered from the dealer.

Rule #2: If you don't have BMW maintenance dough Buy another car. I'm serious These cars are expensive if you want to keep them in top condition. When I bought my E36 I took an extra $4,000 out my bank for fix up cost. I didn't expect to spend even $2,000 of that money on my car within the first year. But in the first month BMW of Manhattan dealership took $2500 from me for basic shit . If you need certain parts, especially cosmetic stuff, EBAY is the best and most convenient place for finding stuff for cheap. I bought my 16 inch alloy Y spoke rims with new Mich tires mounted on them for $400 on ebay as a perfect example!

BOTTOM LINE IS: YES Dealerships are EXPENSIVE and sometimes EVIL but their work is well warrantied and they will take accountabilty if anything goes wrong. Joe Mechanic and his garage dog down the block may be cheaper (not always) but he will act like he never met you before when the cheap ass alternator belts he put in there fall off 6 months later!!!
Not to say that the dealership does perfect work but you can always talk to a manager or someone above the person who screwed up your car if that happens.

if you have the money, delmarco is right, you should go to the stealership... but they are plenty of good mechanics that specialize only in foreign car (and many just german)... atleast in the north east area over here, i know enough... don't know about the chicago area..
but good luck and hopefully they won't find anything wrong...

heres what i did before i bought my 96 328..... when i first saw the car i test drove it (drove quite nicely by the way) spoke to the dealer about car history(dealer was clueless). ran a carfax and checked the history myself, next step was to have the car inspected by a BWM specialist in my area(if you live in a larger city odds are there will be mechs that specialize in bmw's ) during this process i called about 5 mechanics asked them prices on a purchase inspection(between 50-75 dollars)
after that i basically went with the mechanics aptitude to speak english in a proper manor and actually went and looked @ 3 of the shops i called .......after all this i went with a specialist about 10 miles from my house. the dealer let me take the car for the weekend to have it inspected by the mechanic i choose .... mechanic checked it out and to say the least i came out lucky with my car it actually has all the maintenence records up to the 100k maint. mark ....

but those are the steps i took before i bought my 96 328i
hope this helps you out
*edit*
D'oh i just noticed you said you had already purchased the car

I think the idea is that the BMW near me charges over $100 for a full synthetic oil change...if you're not going to do this stuff yourself...find a QUALIFIED mechanic to do it. If you can find one outside of a dealership, even better, due to the fact that BMW charges $100/hr for labor and marks up their parts like 700%.

If you are not going to do this stuff yourself...get familiar with the various BMW parts websites, so you can at least buy the parts at a reaosnable price and then have them installed.

In order to not get ripped off its gonna take either the time to learn how to do the stuff on your own, or the time to research the best place to get it done (which we all know is no easy task).

I went to a "local shop" to change the back brakes backplates. I bought original backplates (20$) and the mechanic removed everything (took 3 hours) but they DID NOT KNOW that you need a special tool to remove the BMW bearings without damaging them... I certainly saved on labor but I had to buy 2 brand new rotors... where's the deal ?

Next time, if I can't afford dealership, I will, AT LEAST, go to a BMW specialist repair shop...